Articulating rod inserter

ABSTRACT

An articulating rod inserter is configured for use in delivering a fixation rod to an orthopedic fixation system through a cannula or tower. The articulating rod inserter is releasably coupled to a rod and can move the rod from a generally aligned configuration, wherein the longitudinal axes of the rod and rod inserter are generally aligned, to an angled configuration, wherein the longitudinal axis of the rod is at an angle to the longitudinal axis of the rod inserter. The rod is inserted into the patient through a first tower and then articulated to a second tower such that the rod extends between two or more fixation devices.

CROSS-REFERENCE TO RELATED APPLICATIONS

Any and all applications for which a foreign or domestic priority claimis identified in the Application Data Sheet as filed with the presentapplication are hereby incorporated by reference under 37 CFR 1.57,including U.S. Provisional Application No. 62/036,053, filed Aug. 11,2014, U.S. patent application Ser. No. 14/822,780, filed Aug. 10, 2015,now U.S. Pat. No. 9,750,546, and U.S. patent application Ser. No.15/694,668, filed Sep. 1, 2017.

BACKGROUND Field

The present disclosure generally relates to the field of spinalorthopedics, and more particularly to a device for introducing a rod toa fixation system through a minimally invasive approach.

Related Art

The spine is a flexible structure that extends from the base of theskull to the tailbone. The weight of the upper body is transferredthrough the spine to the hips and the legs. The spine contains aplurality of bones called vertebrae. The vertebrae are hollow andstacked one upon the other, forming a strong hollow column for support.The hollow core of the spine houses and protects the nerves of thespinal cord. The spine is held upright through the work of the backmuscles, which are attached to the vertebrae. While the normal spine hasno side-to-side curve, it does have a series of front-to-back curves,giving it a gentle “S” shape.

Each vertebra is separated from the vertebra above or below by acushion-like, fibrocartilage called an intervertebral disc. The discsact as shock absorbers, cushioning the spine, and preventing individualbones from contacting each other. In addition, intervertebral discs actas a ligament that holds vertebrae together. Intervertebral discs alsowork with the facet joint to allow for slight movement of the spine.Together, these structures allow the spine to bend, rotate and/or twist.

The spinal structure can become damaged as a result of degeneration,dysfunction, disease and/or trauma. More specifically, the spine mayexhibit disc collapse, abnormal curvature, asymmetrical disc spacecollapse, abnormal alignment of the vertebrae and/or general deformity,which may lead to imbalance and tilt in the vertebrae. This may resultin nerve compression, disability and overall instability and pain. Ifthe proper shaping and/or curvature are not present due to scoliosis,neuromuscular disease, cerebral palsy, or other disorder, it may benecessary to straighten or adjust the spine into a proper curvature withsurgery to correct these spinal disorders.

Fixation is a surgical method wherein two or more vertebrae are heldtogether by the placement of implants to stabilize the vertebrae.Surgical treatments may involve manipulation of the spinal column byattaching corrective implants, such as rods, wires, hooks, screws, andthe like, to straighten abnormal curvatures, appropriately alignvertebrae of the spinal column and/or reduce further rotation of thespinal column. The correct curvature can be obtained by manipulating thevertebrae into their proper position and securing that position with arigid system of screws and rods. The screws can be inserted into thepedicles of the vertebrae to act as bone anchors, and the rods may beinserted into heads of the screws. Two rods may run substantiallyparallel to the spine and secure the spine in the desired shape andcurvature. Thus the rods, which are shaped to mimic the correct spinalcurvature, force the spine into proper alignment.

In many cases, the fixation is augmented by a process called fusion,whereby an interbody implant is positioned in the intervertebral spacebetween two or more vertebrae to join the vertebrae together. Bonegrafts can be placed between the vertebrae and aid in fusion of theindividual vertebrae together to form a correctly aligned spine.

In addition, minimally invasive surgical techniques have been used onthe spine to access the spine through small incisions. Minimallyinvasive spine surgery offers multiple advantages as compared to opensurgery. The advantages may include minimal tissue damage, minimal bloodloss, smaller incisions and scars, minimal post-operative discomfort,and relative quick recovery time and return to normal function.

SUMMARY

An aspect of at least one of the embodiments disclosed herein includes arod inserter for delivering a spinal fixation rod through an accesschannel, the rod inserter including a first member having an elongatetube with a proximal end and a distal end, with a passage extending fromthe proximal end to the distal end. The rod inserter includes a secondmember having an elongate shaft configured to move along the passage ofthe first member and a third member having a first end and a second end,the first end coupled to the second member. The rod inserter furtherincludes a rod holder having a leading end coupled to the distal end ofthe first member and a trailing end coupled to the second end of thethird member, the rod holder configured to transition from an alignedconfiguration, wherein a longitudinal axis of the rod holder isgenerally parallel with a longitudinal axis of the second member, to anangled configuration wherein the longitudinal axis of the rod holder isat an angle to the longitudinal axis of the second member, the rodholder configured to releasably couple with a rod. An actuator towardthe proximal end of the first member can be configured to translate thesecond member, wherein translation of the second member transitions therod holder between the aligned configuration and the angledconfiguration.

The rod holder can automatically release the rod when the rod holder istransitioned toward the aligned configuration. In some embodiments, therod holder has a protrusion configured to be received by a complementarycutout on the rod.

The rod holder can include a mechanism for changing the rod holderbetween a clamping configuration and a release configuration. The secondmember can have a longitudinal channel for accessing the mechanism fromthe proximal end with a drive tool.

In some embodiments, the actuator is a rotating handle. The rotatinghandle can have threads that engage complementary threads on the secondmember to move the second member longitudinally.

The rod inserter can have an indicator corresponding to the orientationof the rod holder relative to the second member. In some embodiments,the rod inserter has an alignment feature configured to cooperate withan access tower, the alignment feature configured to prevent rotation ofthe rod inserter about its longitudinal axis.

An aspect of at least another of the embodiments disclosed hereinincludes a rod inserter having a shaft extending between a proximal endand a distal end of the rod inserter, the shaft having a longitudinalaxis and configured to move along the longitudinal axis. The rodinserter includes a rod holder toward the distal end configured torotate from an aligned configuration wherein a longitudinal axis of therod holder is generally parallel with the longitudinal axis of theshaft, to an angled configuration wherein the longitudinal axis of therod holder is at an angle to the longitudinal axis of the shaft, the rodholder configured to releasably couple with a rod. An actuator towardthe proximal end is configured to transition the rod holder between thealigned configuration and angled configuration.

In some embodiments, the rod holder has a leading end pivotally coupledto the distal end of the rod inserter and a trailing end coupled to theshaft. The shaft can be connected to the rod holder by one or morelinkages.

The rod holder can automatically releases the rod when the rod holder istransitioned toward the aligned configuration. In some embodiments, therod holder has a protrusion configured to be received by a complementarycutout on the rod.

The rod holder can include a mechanism for changing the rod holderbetween a clamping configuration and a release configuration. The shaftcan have a longitudinal channel for accessing the mechanism from theproximal end with a drive tool.

In some embodiments, the actuator is a rotating handle. The rotatinghandle can have threads that engage complementary threads on the shaftto move the shaft longitudinally.

The rod inserter can have an indicator corresponding to the orientationof the rod holder relative to the shaft. In some embodiments, the rodinserter has an alignment feature configured to cooperate with an accesstower, the alignment feature configured to prevent rotation of the rodinserter about its longitudinal axis.

An aspect of at least one of the embodiments disclosed herein includes amethod of delivering a rod onto a fixation system, the method includingproviding a rod inserter having a rod holder configured to rotate froman aligned configuration wherein a longitudinal axis of the rod holderis generally parallel with a longitudinal axis of the rod inserter, toan angled configuration wherein the longitudinal axis of the rod holderis at an angle to the longitudinal axis of the rod inserter, and furtherproviding a rod releasably coupled to the rod holder. The method canfurther include inserting the rod longitudinally through an accesschannel of a first anchoring device and activating an actuator on therod inserter to transition the rod holder from the aligned configurationto the angled configuration, such that a trailing end of the rod is nearthe first anchoring device and a leading end of the rod is near a secondanchoring device.

In some embodiments, the method further includes activating the actuatorto transition the rod holder from the angled configuration to thealigned configuration, wherein the rod holder automatically releases therod. The method can further include moving a mechanism that releases therod from the rod holder.

The method can further include securing the rod to the first or secondanchoring device. Securing the rod to the first or second anchoringdevice can include fastening a threaded cap onto the first or secondanchoring device.

In some embodiments, the first and second anchoring devices are pediclescrews with heads adapted to receive the rod.

BRIEF DESCRIPTION OF THE DRAWINGS

Specific embodiments and modifications thereof will become apparent tothose skilled in the art from the detailed description herein havingreference to the figures that follow, of which:

FIG. 1 is a perspective view of a rod inserter with a rod attached,according to an embodiment of the present disclosure.

FIG. 2 is a side view of the rod inserter and rod of FIG. 1.

FIG. 3 is a perspective view of the rod of FIG. 1.

FIG. 4 is a side view of the rod of FIG. 3.

FIG. 5 is a close-up perspective view showing the rod holder of the rodinserter of FIG. 1 without a rod.

FIG. 6 is a close-up perspective view showing the rod holder of the rodinserter of FIG. 1 with a rod attached.

FIG. 7 is a close-up perspective view showing the rod holder of the rodinserter of FIG. 1 with a rod attached, shown with portions of the rodinserter as transparent.

FIG. 8 is a cross-sectional side view of the proximal end of the rodinserter of FIG. 1.

FIG. 9 is a cross-sectional side view of the distal end of the rodinserter and rod of FIG. 1.

FIG. 10 is a close-up side view of the rod inserter of FIG. 1 showing anangle indicator window.

FIG. 11 is a perspective view of the rod inserter of FIG. 1 positionedabove pedicle screws with towers attached.

FIG. 12 is a perspective view of the rod inserter of FIG. 1 beinginserted into a tower.

FIG. 13 is a perspective view of the rod inserter of FIG. 1 insertedinto a tower and a leading end of the rod near the pedicle screw.

FIG. 14 is a perspective view of the rod inserter of FIG. 1 insertedinto a tower and being actuated to move the rod partially toward asecond tower.

FIG. 15 is a perspective view of the rod inserter of FIG. 1 insertedinto a tower and a leading end of the rod positioned in a second tower.

FIG. 16 is a perspective view of the rod inserter of FIG. 1 insertedinto a tower and the rod extending between two towers.

FIG. 17 is a perspective view of the rod inserter of FIG. 1 insertedinto a tower and a fastener driver inserted into another tower.

FIG. 18 is a perspective view of the rod inserter of FIG. 1 insertedinto a tower and being actuated to retract the rod holder.

FIG. 19 is a perspective view of the rod inserter of FIG. 1 removed froma tower.

FIG. 20 is a close-up perspective view of a rod holder of a rodinserter, according to another embodiment of the present disclosure.

FIG. 21 is a close-up perspective view of the rod holder of FIG. 20,shown with a rod.

FIG. 22 is a perspective view of the rod of FIG. 21.

FIG. 23 is a side view of the rod of FIG. 21.

FIG. 24 is a perspective view of the first arm of the rod holder of FIG.20.

FIG. 25 is a perspective view of the second arm of the rod holder ofFIG. 20.

FIG. 26 is a perspective cross-sectional view of a mechanism of the rodholder of FIG. 20.

FIG. 27 is a close-up perspective view of the rod holder of FIG. 20,shown with a rod and portions of the rod inserter as transparent.

FIG. 28 is a close-up cross-sectional side view of the rod holder ofFIG. 27.

FIG. 29 is a perspective view of the rod inserter of FIG. 20, shown witha drive tool and a rod.

FIG. 30 is a close-up cross-sectional side view of the rod holder ofFIG. 29, with the drive tool and rod.

DETAILED DESCRIPTION

Devices and methods of fixing two or more vertebrae are disclosed hereinand in some embodiments can involve minimally invasive techniques.Several non-limiting embodiments will now be described with reference tothe figures, wherein like numerals reflect like elements throughout. Theterminology used in the description presented herein is not intended tobe interpreted in any limited or restrictive way, simply because it isbeing utilized in conjunction with a detailed description of certainspecific embodiments. Furthermore, some embodiments may include severalnovel features, no single one of which is solely responsible for itsdesirable attributes or which is essential to the devices and methodsdescribed herein.

The words proximal and distal are applied herein to denote specific endsof components of the instrument described herein. A proximal end refersto the end of a component nearer to an operator of the instrument whenthe instrument is being used. A distal end refers to the end of acomponent further from the operator and extending towards the surgicalarea of a patient and/or the implant. The words top, bottom, left,right, upper and lower are used herein to refer to sides of the devicefrom the described point of view. These reference descriptions are notintended to limit the orientation of the implant tool and the device canbe used in any functional orientation.

FIGS. 1 and 2 illustrate a rod inserter 100 having a rod 200 attached.The illustrated rod inserter 100 is an elongate tool used to deliver,and in some situations reduce, a rod onto a spinal fixation system. Therod inserter 100 has a proximal end 102 and a distal end 104. Theproximal end 102 can have a handle 110 and the distal end 104 can have arod holder 120 that is configured to releasably couple with the rod 200.An elongate tube 130 can extend from the handle 110 to the rod holder120. An alignment feature 136 can be disposed on the rod inserter 100 tohelp with proper orientation of the rod inserter 100 during insertioninto the towers, as described below.

As illustrated in FIGS. 3 and 4, the rod 200 can be an elongate memberconfigured to extend between two or more bone anchors that are fixed totwo or more vertebrae. In the illustrated embodiment, the rod 200 has anelongate cylindrical shape with a trailing end 202 and a leading end204. In other embodiments, the rod can have other shapes, such aselongate members with an oval, square, rectangular, or polygonalcross-sectional shape. The illustrated rod 200 has a slight bend orcurve, which may help the fixation system to preserve the natural shapeof the spinal anatomy. In other embodiments, the rod can besubstantially straight, have a greater curve than the illustratedembodiment, or have multiple bends.

The trailing end 202 of the rod 200 can have a coupling feature toaccept a complementary feature on the rod holder 120. For example, theillustrated rod 200 has a cutout 206 with a round shape that iscomplementary to the shape of a protrusion 122 or clip on the rod holder120, as shown in FIG. 5. The protrusion 122 can have a slot through themiddle that allows the sides of the protrusion to deflect in order torelease from the cutout 206 of the rod 200. In some embodiments, theprotrusion can have a different release design, such as the protrusionbeing made of a compressible material that compresses to release fromthe cutout. The protrusion 122 can be customized so that it releasesfrom the rod 200 at a predetermined amount of separation force. In otherembodiments, the coupling feature between the rod and rod holder can beany functional coupler that disconnects with a predetermined amount ofseparation force. The position of the protrusion 122 on the rod holder120 can be tailored so that the rod has a predetermined amount ofoverhang from the fixation device when implanted. The amount of overhangcan be selected for optimized efficacy.

A first end of the rod holder 120 is hingedly coupled to the distal endof the tube 130. A second end of the rod holder 120 is hingedly coupledto a distal end of a linkage 150. In the illustrated embodiment, thehinged couplings comprise pins. In other embodiments, the hingedcoupling can be any functional hinge, such as screws, ball and sockets,bending joints, friction connections, and the like.

With continued reference to FIG. 5, the linkage 150 in the illustratedembodiment comprises two struts 152 attached to either side of the rodholder 120, leaving space between the struts 152 to accommodate the rodholder 120 when rotated. A middle piece can be disposed between the twostruts 152 for increased structural strength. In some embodiments, thelinkage 150 can be a single component with a forked distal end toaccommodate the rod holder. The proximal end of the linkage 150 ishingedly coupled to a distal end of a shaft 140. The hinged coupling caninclude pins or other functional coupler, as discussed above. The shaft140 is an elongate member that extends through the middle of the tube130 to transition the rod holder, and thus the rod, from an alignedconfiguration to an angled configuration, as discussed further below.

With reference to FIG. 6, the rod 200 can be releasably coupled with therod holder 120 such that the rod 200 can be automatically separated fromrod inserter 100. As used herein, automatically separated meansseparation without directly releasing the rod 200. For example, when therod is secured to the fixation system and the rod holder 120 isretracted, the rod holder 120 and rod 200 are pulled apart until theprotrusion 122 is separated from the cutout 206. The rod 200 is releasedautomatically as a result of the retraction of the rod holder 120,without having to directly uncouple the rod 200 or have a secondaryrelease mechanism.

In some embodiments, the rod and rod holder can have other suitableshapes or configurations that allow releasable attachment of the rod tothe rod holder. For example, the rod 200 and rod holder 120 can bereleasably attached with adhesives, clips, magnets, snaps, compressionjoints or other suitable releasable connections. In some embodiments,the cutout can be disposed on the rod holder and the protrusion can bedisposed on the rod.

The leading end 204 of the rod 200 can be bulleted with an angledsurface 208 to help the rod move through the patient's tissue andmuscle. Preferably, the tip of the leading end 204 is blunt to minimizetrauma to the surrounding tissue as the rod 200 is positioned onto thebone anchors. The leading end 204 can have a hole 210 that helpsvisualize the rod 200 during the implantation procedure, such as whenusing X-ray or fluoroscopic imaging techniques. The hole 210 can producea contrasting image compared to the surrounding rod so that surgeons canvisualize the location of the leading end 204. In some embodiments, therod can include radiopaque markers (e.g., tantalum, titanium, etc.) thatcan be seen in X-ray or other imaging techniques.

FIG. 7 illustrates the distal end 104 of the rod inserter 100 with thetube 130 shown as transparent. The shaft 140 is shown extending throughthe middle of the tube 130. The proximal end of the shaft 140 is coupledto an actuator on the handle and the shaft 140 is configured to slidelongitudinally through the tube 130 when the actuator is activated. Asthe shaft 140 moves along the longitudinal direction, the shaft 140pushes the proximal end of the linkage 150, causing the distal end ofthe linkage 150 to pivot out at least partially in the lateraldirection, transitioning the rod holder 120 between an alignedconfiguration and an angled configuration, as described in furtherdetail below.

The shaft 140 can be configured to move in the longitudinal direction,but constrained from rotating about the longitudinal axis. In theillustrated embodiment, the shaft 140 and the linkage 150 are rotatablyconnected with a pin 142. The pin 142 extends beyond the connectionbetween the shaft 140 and linkage 150 and through a slot 132 in the tube130. The slot 132 is an elongate cutout extending longitudinally in theside walls of the tube 130. As the actuator is activated, the shaft 140can be constrained from rotating by the pin 142 in the slot 132, butallowed to move longitudinally along the length of the slot 132. Inother embodiments, the shaft 140 may have a separate protrusion or pinapart from pin 142 that is configured to slide within the slot 132. Insome embodiments, the shaft can have other configurations that permitlongitudinal movement and constrain rotational movement. For example,the shaft can have a non-circular cross-sectional shape, such as anoval, square, or polygon, and the inner cavity of the tube can have acomplementary shape, such that the tube blocks rotation of the shaft.

FIG. 8 illustrates a cross-sectional view of the proximal portion of arod inserter 100 according to some embodiments. The handle 110 cancomprise a fixed portion 112 and an actuator portion 114. The fixedportion 112 is rigidly connected to the tube 130 and the actuatorportion 114 can rotate or otherwise move relative to the fixed portion112. The actuator portion 114 can be activated to drive the shaft 140 inthe longitudinal direction. In the illustrated embodiment, the shaft 140has a proximal end 144 that is engageable with the actuator portion 114of the handle 110. For example, the proximal end 144 of the shaft 140can have external threads 146 that engage with internal threads 116 onthe actuator portion 114. When the illustrated actuator portion 114 isrotated, the internal threads 116 cooperate with the external threads146 of the proximal end 144 to move the proximal end 144 and the shaft140 in the proximal-distal direction. As mentioned above, the shaft 140can be constrained from rotating by the pin 142 in the slot 132, butallowed to move longitudinally along the length of the slot 132. Inother embodiments, the proximal portion of the rod inserter can haveother actuation mechanisms for translating the shaft 140, such as aratcheting handle or a trigger style mechanism or any other suitabletranslation mechanism.

With reference to FIG. 9, the shaft 140 can be moved in theproximal-distal direction to transition the rod 200 between an alignedconfiguration, wherein the longitudinal axis 201 of the rod 200 and thelongitudinal axis 106 of the rod inserter 100 are generally aligned, toan angled configuration, wherein the longitudinal axis 201 of the rod200 is at an angle to the longitudinal axis 106 of the rod inserter 100.As the actuator portion 114 of the handle 110 shown in FIG. 8 isactivated, the shaft 140 moves in the longitudinal direction and actsupon the proximal end of the linkage 150. When the shaft 140 is moved inthe distal direction, the proximal end of the linkage 150 also moves inthe distal direction causing the distal end of the linkage 150 to swingout laterally. The distal end of the linkage 150 is attached to thesecond end of the rod holder 120, which also swings out laterally,transitioning the rod holder 120 from an aligned configuration to anangled configuration shown in FIG. 9. Since the rod 200 is releasablycoupled to the rod holder 120, the rod 200 is also transitioned from analigned configuration to an angled configuration by activating theactuator portion 114 of the handle 110.

As illustrated in FIG. 10, in some embodiments, the tube 130 can have awindow 134 with a display that indicates the position of the rod 200.The window 134 is configured to be visible from outside the incision sothat the surgeon can know the orientation of the rod 200 withoutdirectly viewing inside the implant site. For example, the shaft 140 canbe marked along the longitudinal length with angle indicators thatcorrespond to the angle of the rod 200 relative to the tube 130. As theshaft 140 moves in the longitudinal direction, the indicated angledisplayed through the window changes with the angle of the rod 200. Theindicated angle can start from 0 degrees, indicating that the rod 200 isgenerally longitudinally aligned with the tube 130, to about 90 degrees,indicating that the rod 200 is generally perpendicular to the tube 130.In some embodiments, the indicated angle can go higher than 90 degrees,indicating that the rod 200 is oriented beyond perpendicular to the tube130. In other embodiments, the display can simply be sequential numbers,letters, symbols, or other markings that indicate the orientation of therod.

In a method of using the rod inserter 100, the vertebral column isaccessed and one or more vertebrae are identified and accessed. In someembodiments, the upper cervical spine is accessed. In other embodiments,the lower cervical spine, cervicothoracic junction, thoracic spine,thoracolumbar junction, lumbar region, lumbosacral junction, sacrum orcombination of the above regions are accessed. Two or more vertebrae areaccessed and in some embodiments, two or more adjacent vertebrae areaccessed.

In a minimally invasive technique, the vertebrae can be accessed throughtwo small incisions that are made near the selected vertebrae. Theincisions can be just large enough to accommodate access cannulas ortowers. In some embodiments, the vertebral column can be accessedthrough an incision that is large enough to access the two or morevertebrae in an open procedure.

With reference to FIG. 11, a first pedicle screw 300, or other anchoringdevice, can be implanted in a first vertebra. A first tower 400 can beattached to the pedicle screw 300 before being implanted or afterimplantation. A second pedicle screw 310, or other anchoring device, canbe implanted in a second vertebra. A second tower 410 can be attached tothe second pedicle screw 310 before being implanted or afterimplantation. The towers 400, 410 can be elongate tubes or cannulas withan inner channel through which devices and instruments can be insertedto reach the pedicle screws 300, 310 from a remote proximal locationoutside the incision. The pedicle screws can have threaded shanks thatare configured to be screwed into and retained by vertebral bone. Theheads of the pedicle screws can be configured to accept a rod. Forexample, the illustrated embodiment of the pedicle screw heads include aU-shaped structure with internal threads, wherein the rod is held in theU-shaped cutout and retained by a threaded cap or a nut with externalthreads.

After the two or more pedicle screws are implanted in the vertebrae, therod inserter 100 with the rod 200 attached can be positioned above oneof the towers. In the embodiment illustrated in FIG. 11, the rod 200 isgenerally longitudinally aligned with the rod inserter 100 inpreparation for insertion in the first tower 400. The rod inserter 100is oriented such that the rod 200 can be angled toward the second tower410. In some embodiments, the rod inserter 100 can have alignmentfeatures 136 that engage with features on the towers to help orient therod inserter 100 in the desired direction. In the illustratedembodiment, the alignment features 136 are protrusions on the tube 130that are inserted into longitudinal slots on the towers. The illustratedembodiment has two elongate protrusions on opposite sides of the rodinserter 100, however, in other embodiments the alignment feature can beany suitable feature, such as directional indicators on the handle 110tip or tube 130.

FIG. 12 illustrates the rod 200 being inserted into the first tower 400.The rod 200 is generally longitudinally aligned with the first tower 400as it is inserted into the tower 400. FIG. 13 illustrates the rod 200and rod inserter 100 advanced further down the first tower 400. Thealignment feature 136 is coupled with slots in the tower 400, whichhelps orient the rod inserter 100 in the proper direction for advancingthe rod 200 to the second tower 410. The alignment feature 136 can alsohelp prevent the rod 200 from being inadvertently misaligned or rotatedabout the longitudinal axis of the tower 400. The rod 200 is shownnearing the bottom of the first tower 400 and top of the first pediclescrew 300. As the rod 200 approaches or reaches the top of the firstpedicle screw 300, the actuator portion 114 of the handle 110 can beactivated (e.g., rotated) to start angling the rod 200 relative to thelongitudinal axis of the first tower 400 and rod inserter 100, asillustrated in FIG. 14. The leading end 204 of the rod 200 can move outof the tower 400 through openings that are disposed on the sides of thetowers.

With reference to FIG. 15, as the actuator portion 114 is furtheractivated, the leading end 204 of the rod 200 continues to move towardthe second tower 410. The rod inserter 100 can be moved further distallydown the first tower 400 as the rod 200 is angled relative to the tube130. The leading end 204 of the rod 200 can move through openings in thesecond tower 410 and through the channel of the second tower 410.

FIG. 16 illustrates the rod 200 seated in the heads of the pediclescrews 300, 310. In the illustrated embodiments, the rod 200 isgenerally perpendicular to the tube 130, or generally parallel with thespinal column. In other embodiments, the rod 200 can be at other anglesto suit the positions of the pedicle screws and/or anatomy of thepatient. Advantageously, the amount of rod overhang from the pediclescrews can be controlled when using the rod inserter 100. When the rod200 is generally perpendicular to the tube 130, a set length of the rodextends beyond the longitudinal axis of the rod inserter 100. This setlength becomes the overhang from the pedicle screws once the rod 200 isattached to the pedicle screw. Therefore, a predetermined overhang canbe achieved with the rod inserter 100 by tailoring the design of the rodholder 120 to control the set length that the rod 200 extends beyond thelongitudinal axis of the rod inserter 100 when in the angledconfiguration.

FIG. 17 illustrates the rod inserter 100 in the first tower 400, and afastener driver 500 and/or reducer in the second tower 410. The fastenerdriver 500 is an elongate tool that is configured for insertion throughthe tower to deliver and couple a fastener, such as a threaded cap, tothe head of a pedicle screw. In the illustrated embodiment, the fastenerdriver 500 is positioned through the second tower 410 and a threaded capis fastened to the second pedicle screw 310, which tightens against therod 200 to fix the leading end 204 of the rod 200.

After the leading end 204 of the rod 200 is fixed to the second pediclescrew 310, the actuator portion 114 can be activated in reverse toretract the rod holder 120 back into the tube 130, as illustrated inFIG. 18. Since the rod 200 is held in place on the second pedicle screwby the threaded cap, other fastener or tool, when the rod holder 120 isretracted it separates from the rod 200. As described above, thereleasable mechanism holding the rod 200 and rod holder 120 togetherdisconnects when the two components are separated with sufficient force.

Once the rod holder 120 is fully retracted, the rod inserter 100 can beremoved from the first tower 400, as illustrated in FIG. 19. In someembodiments, the fastener driver 500 can be inserted into the firsttower 400 to attach a fastener to the first pedicle screw to secure thetrailing end 202 of the rod 200. After the rod 200 is secured, thetowers 400 and 410 can be removed and the one or more incisions closed.

In some configurations, a second set of anchoring devices is attached tothe same vertebrae on the other side of the posterior arch. In otherconfigurations, the second set of anchoring devices can be attached todifferent vertebrae. A second elongate member or rod 200 can be used tocouple the second set of anchoring devices. In some configurations, thetwo rods 200 are generally parallel to each other. In otherconfigurations, the two rods 200 can be at an angle to each other and/ordifferent distances along the posterior-anterior direction.

Another embodiment of a rod inserter 600 is illustrated in FIG. 20 withanother embodiment of a rod holder 620. The rod holder 620 can have amechanism 660 that is actuated to transition the rod holder 620 from afirst configuration to a second configuration. In the firstconfiguration, the rod holder 620 can grasp the rod and in the secondconfiguration the rod holder can release the rod. In some embodiments,the mechanism 660 is a screw that is disposed between a first arm 621and a second arm 622 and is configured to bring the arms 622, 622 towardeach other, as described further below. In some embodiments, themechanism can have a cam connection, angled surfaces, or otherconfiguration to bring the arms together. The handle, tube 630 andlinkage 650 can be similar to other embodiments of the rod inserterdescribed above.

With reference to FIGS. 20 and 21, the first arm 621 and second arm 622can be configured to overlap each other and can be pivotally linkedtoward the center such that the arms 621, 622 move in a scissor-likemotion. In the illustrated embodiment, the arms 621, 622 are connectedby a hinge having a pin 626 with a longitudinal axis parallel with theaxis of rotation of the arms 621, 622. In other embodiments, the armscan have any functional joint that provides pivotal movement, such asfor example a ball-and-socket. As illustrated in FIGS. 20, 24 and 25,the arms 621, 622 can have a leading engagement portion 624 and atrailing engagement portion 625 that are configured to couple with arod. The leading engagement portion 624 is comprised of side wallsconfigured to extend around the rod 700. The inner surface of theleading engagement portion 624 can be curved to correspond to thecurvature of the rod to help engage and secure the rod. The trailingengagement portion 625 is comprised of side walls with an openingbetween the walls configured to engage the trailing end 702 of the rod700.

With reference to FIGS. 22 and 23, the rod 700 is an elongate memberconfigured to extend between two or more bone anchors that are fixed totwo or more vertebrae. In the illustrated embodiment, the rod 700 has anelongate cylindrical shape with a trailing end 702 and a leading end704. In other embodiments, the rod can have other shapes, such aselongate members with an oval, square, rectangular, or polygonalcross-sectional shape. In some embodiments, the rod can be substantiallystraight or have a curve, which may help the fixation system to conformwith the natural shape of the spinal anatomy.

In the illustrated embodiment, the trailing end 702 has a reducedthickness that fits between the side walls of the trailing engagementportion 625 of the rod holder 620. The trailing end 702 can have a knob706 that couples with a cavity 627 in the trailing engagement portion625 to help retain the rod 700 on the rod holder 620. In the illustratedembodiment, the knob 706 has flanges 708 that are configured to engagewith shoulders 628 (see FIG. 25) in the cavity 627 of the trailingengagement portion 625 to help prevent the rod from falling out of thetrailing engagement portion 625. The knob 706 can also have a projection710 that blocks the rod 700 from moving longitudinally when coupled tothe cavity 627 of the trailing engagement portion 625. In otherembodiments, the knob can have other features to help secure the rod toa complementary cavity in the trailing engagement portion, such as forexample hooks, magnets, textured surfaces, and the like.

Actuating the mechanism 660 can close the arms 621, 622 to a firstconfiguration wherein the arms 621, 622 clamp around the rod 700. Withreference to FIG. 21, the leading engagement portion 624 clamps onto themiddle portion of rod 700 and the trailing engagement portion 625 clampsonto the trailing end 702 of the rod 700. In the embodiment illustratedin FIG. 24, the first arm 621 and the second arm 622 have a hole withinternal threads 665. A dome 667 with sloped sides 669 can be disposedat the bottom of the hole and can be configured to engage the mechanism660.

With reference to FIG. 26, the mechanism 660 can be a setscrew having adrive feature 662 on top and an aperture on the bottom with an angledbottom surface 668. The drive feature 662 is illustrated as a hex drive,but can be any of a plurality of different types of drive features, suchas a Torx drive, slotted drive, and the like. The sides of the mechanism660 can have external threads 664 that are complementary to the internalthreads 665 of the arms 621, 622. When the mechanism 660 is screwed intothe arms 621, 622, the angled bottom surface 668 of the mechanism 660contacts the angled sides 669 of the dome 667. As the mechanism 660 isadvanced further, the angled surfaces cooperate to squeeze the first arm621 and second arm 622 together and close the leading engagement portion624 in the first configuration. At the same time, the hinging action ofthe two arms 621, 622 closes the trailing engagement portion 625 in thefirst configuration.

The mechanism can be any of a plurality of different types of engagementdevices configured to draw the two arms together, such as for example aclamp, a cam mechanism, or a fastener. In some embodiments, the arms canclamp in other ways. For example, the rod holder may pivot along itslongitudinal axis and a wedge inserted in the top portion of the rodholder can close the engagement portions on the bottom portion of therod holder. In another example, advancing a mechanism can drive a wedgebetween the rod holder and the rod to secure the rod. Other arrangementsfor securing the rod are also contemplated.

With reference to FIGS. 27 and 28, when the rod holder is generallyperpendicular to the longitudinal axis of the shaft 640, the drivefeature 662 of the mechanism 660 is generally aligned with thelongitudinal axis of the shaft 640. As illustrated in FIG. 28, the shaft640 can have a channel 648 that extends through the longitudinal lengthof the shaft 640. The channel 648 is configured to provide access to themechanism 660 from the top of the rod inserter 600. A drive tool can beinserted through the channel 648 to engage the mechanism 660 and changethe rod holder 620 between the first and second configurations. When therod holder is generally parallel to the longitudinal axis of the shaft640, the mechanism 660 can be accessed and actuated through a cutout 638on the side of the tube 630, as illustrated in FIGS. 27 and 28.

FIG. 29 illustrates an embodiment of a rod inserter 600 with a drivetool 680 inserted through the rod inserter 600 to actuate the mechanism660. The drive tool 680 protrudes proximally from the handle of the rodinserter 600 and can be conveniently manipulated from outside of thesurgical incision. As illustrated in FIG. 30, the drive tool 680 extendsthrough the channel 648 of the shaft 640 and the distal end of the drivetool 680 is configured to engage the drive feature 662 of the mechanism660. As discussed above, the drive feature 662 can be a hex drive, aTorx drive, slotted, or any other functional drive feature. The distalend of the drive tool 680 has a complementarily shaped hex head, Torxhead, flathead, etc. to engage the drive feature 662.

Methods of using the alternative embodiments of the rod inserter aresimilar to as described above for other embodiments. The vertebralcolumn is accessed and one or more vertebrae are identified andaccessed. In a minimally invasive technique, the vertebrae can beaccessed through two small incisions that are made near the selectedvertebrae. The incisions can be just large enough to accommodate accesscannulas or towers. In some embodiments, the vertebral column can beaccessed through a single incision that is large enough to access thetwo or more vertebrae in an open procedure.

As described above, a first pedicle screw and a first tower can beattached to a first vertebra. A second pedicle screw and a second towercan be attached to a second vertebra. Then, the rod inserter 600 withthe rod 700 attached can be positioned above one of the towers. The rod700 is generally longitudinally aligned with the rod inserter 600 inpreparation for insertion in the first tower. The rod inserter 600 isoriented such that the rod 700 can be angled toward the second tower.

The rod inserter 600 can have alignment features that engage withfeatures on the towers to help orient the rod inserter 600 in thedesired direction, as described above in other embodiments. In theillustrated embodiments, the alignment feature couples with slots in thetower, which help orient the rod inserter 600 in the proper directionfor advancing the rod 700 toward the second tower. The alignment featurecan also help prevent the rod 700 from being inadvertently misaligned orrotated about the longitudinal axis of the tower.

As the rod 700 approaches or reaches the top of the first pedicle screw,the actuator portion of the handle can be activated (e.g., rotated) tostart angling the rod 700 relative to the longitudinal axis of the firsttower and rod inserter 600. The leading end 704 of the rod 700 can moveout of the tower through openings that are disposed on the sides of thetowers. As the actuator portion is further activated, the leading end704 of the rod 700 continued to move toward the second tower. The rodinserter 600 can be moved further distally down the first tower as therod 700 is angled. The leading end 704 of the rod 700 can move throughside openings in the second tower and through the channel of the secondtower.

The rod 700 can be seated in the heads of the pedicle screws, where therod 700 can be generally perpendicular to the tube of the rod inserter600, or generally parallel with the spinal column. In other embodiments,the rod 700 can be at other angles to suit the positions of the pediclescrews and/or anatomy of the patient. In some embodiments, a fastenerdriver is inserted in the second tower to deliver and couple a fastener,such as a threaded cap, to the head of a pedicle screw. The fastener istightened against the rod 700 to fix the leading end 704 of the rod 700.

A drive tool 680 can be inserted through the channel 648 of the rodinserter 600 from the proximal end to the rod holder 620 at the distalend. The drive tool 680 is configured to engage and actuate themechanism 660. As described above, actuating the mechanism 660 releasesthe rod 700 from the rod holder 620. After the rod 700 is released fromthe rod holder 620, the drive tool 680 can be removed from the rodinserter 600.

The actuator portion can be activated in reverse to retract the rodholder 620 back into the tube. Once the rod holder 620 is retracted, therod inserter 600 can be removed from the first tower. In someembodiments, a fastener driver can be inserted into the first tower toattach a fastener to the first pedicle screw to secure the trailing end702 of the rod 700. After the rod 700 is secured, the towers can beremoved and the one or more incisions closed.

In some configurations, a second set of anchoring devices is attached tothe same vertebrae on the other side of the posterior arch. In otherconfigurations, the second set of anchoring devices can be attached todifferent vertebrae. A second elongate member or rod 700 can be used tocouple the second set of anchoring devices. In some configurations, thetwo rods 700 are generally parallel to each other. In otherconfigurations, the two rods 700 are at an angle to each other.

Although certain embodiments, features, and examples have been describedherein, it will be understood by those skilled in the art that manyaspects of the methods and devices illustrated and described in thepresent disclosure may be differently combined and/or modified to formstill further embodiments. For example, any one component of the deviceillustrated and described above can be used alone or with othercomponents without departing from the spirit of the present disclosure.Additionally, it will be recognized that the methods described hereinmay be practiced in different sequences, and/or with additional devicesas desired. Such alternative embodiments and/or uses of the methods anddevices described above and obvious modifications and equivalentsthereof are intended to be included within the scope of the presentdisclosure. Thus, it is intended that the scope of the presentdisclosure should not be limited by the particular embodiments describedabove, but should be determined only by a fair reading of the claimsthat follow.

What is claimed is:
 1. A rod inserter for delivering a spinal fixationrod through an access channel, the rod inserter comprising: a firstmember comprising an elongate tube with a proximal end and a distal end,with a passage extending from the proximal end to the distal end; asecond member comprising an elongate shaft configured to move along thepassage of the first member; a third member comprising a first end and asecond end, the first end coupled to the second member; a rod holdercomprising a leading end coupled to the distal end of the first memberand a trailing end coupled to the second end of the third member, therod holder configured to transition from an aligned configuration,wherein a longitudinal axis of the rod holder is generally parallel witha longitudinal axis of the second member, to an angled configurationwherein the longitudinal axis of the rod holder is at an angle to thelongitudinal axis of the second member, the rod holder configured toreleasably couple with a rod; and an actuator toward the proximal end ofthe first member configured to translate the second member, whereintranslation of the second member transitions the rod holder between thealigned configuration and the angled configuration.
 2. The rod inserterof claim 1, wherein the rod holder automatically releases the rod whenthe rod holder is transitioned toward the aligned configuration.
 3. Therod inserter of claim 2, wherein the rod holder comprises a protrusionconfigured to be received by a complementary cutout on the rod.
 4. Therod inserter of claim 1, wherein the rod holder comprises a mechanismfor changing the rod holder between a clamping configuration and arelease configuration.
 5. The rod inserter of claim 4, wherein thesecond member comprises a longitudinal channel for accessing themechanism from the proximal end with a drive tool.
 6. The rod inserterof claim 1, wherein the actuator is a rotating handle.
 7. The rodinserter of claim 6, wherein the rotating handle comprises threads thatengage complementary threads on the second member to move the secondmember longitudinally.
 8. The rod inserter of claim 1, furthercomprising an indicator corresponding to the orientation of the rodholder relative to the second member.
 9. The rod inserter of claim 1,further comprising an alignment feature configured to cooperate with anaccess tower, the alignment feature configured to prevent rotation ofthe rod inserter about its longitudinal axis.
 10. A rod insertercomprising: a shaft extending between a proximal end and a distal end ofthe rod inserter, the shaft comprising a longitudinal axis andconfigured to move along the longitudinal axis; a rod holder toward thedistal end configured to rotate from an aligned configuration wherein alongitudinal axis of the rod holder is generally parallel with thelongitudinal axis of the shaft, to an angled configuration wherein thelongitudinal axis of the rod holder is at an angle to the longitudinalaxis of the shaft, the rod holder configured to releasably couple with arod; and an actuator toward the proximal end configured to transitionthe rod holder between the aligned configuration and angledconfiguration.
 11. The rod inserter of claim 10, wherein the rod holdercomprises a leading end pivotally coupled to the distal end of the rodinserter and a trailing end coupled to the shaft.
 12. The rod inserterof claim 10, wherein the shaft is connected to the rod holder by one ormore linkages.
 13. The rod inserter of claim 10, wherein the rod holderautomatically releases the rod when the rod holder is transitionedtoward the aligned configuration.
 14. The rod inserter of claim 13,wherein the rod holder comprises a protrusion configured to be receivedby a complementary cutout on the rod.
 15. The rod inserter of claim 10,wherein the rod holder comprises a mechanism for changing the rod holderbetween a clamping configuration and a release configuration.
 16. Therod inserter of claim 15, wherein the shaft comprises a longitudinalchannel for accessing the mechanism from the proximal end with a drivetool.
 17. The rod inserter of claim 10, wherein the actuator is arotating handle.
 18. The rod inserter of claim 17, wherein the rotatinghandle comprises threads that engage complementary threads on the shaftto move the shaft longitudinally.
 19. The rod inserter of claim 10,further comprising an indicator corresponding to the orientation of therod holder relative to the shaft.
 20. The rod inserter of claim 10,further comprising an alignment feature configured to cooperate with anaccess tower, the alignment feature configured to prevent rotation ofthe rod inserter about its longitudinal axis.
 21. A method of deliveringa rod onto a fixation system, the method comprising: providing a rodinserter comprising a rod holder configured to rotate from an alignedconfiguration wherein a longitudinal axis of the rod holder is generallyparallel with a longitudinal axis of the rod inserter, to an angledconfiguration wherein the longitudinal axis of the rod holder is at anangle to the longitudinal axis of the rod inserter, and furtherproviding a rod releasably coupled to the rod holder; inserting the rodlongitudinally through an access channel of a first anchoring device;and activating an actuator on the rod inserter to transition the rodholder from the aligned configuration to the angled configuration, suchthat a trailing end of the rod is near the first anchoring device and aleading end of the rod is near a second anchoring device.
 22. The methodof delivering a rod of claim 21, further comprising activating theactuator to transition the rod holder from the angled configuration tothe aligned configuration, wherein the rod holder automatically releasesthe rod.
 23. The method of delivering a rod of claim 21, furthercomprising moving a mechanism that releases the rod from the rod holder.24. The method of delivering a rod of claim 21, further comprisingsecuring the rod to the first or second anchoring device.
 25. The methodof delivering a rod of claim 24, wherein securing the rod to the firstor second anchoring device comprises fastening a threaded cap onto thefirst or second anchoring device.
 26. The method of delivering a rod ofclaim 21, wherein the first and second anchoring devices are pediclescrews with heads adapted to receive the rod.